The present invention relates to a method for making an electrical circuit board and more particularly, to a method for making a multi-layer electrical circuit board having pipes, tunnels and/or caverns which are formed within the circuit board and/or through various portions of the circuit board, and heat pumps which communicate with the pipes, tunnels, and/or caverns and which allow heat emanating from components which are contained within the circuit board to be efficiently dissipated.
Multi-layer circuit boards contain and/or include electrical components which selectively and operatively populate opposed first and second surfaces (i.e., top and bottom surfaces) of each board (or other respective interior portions of each board), thereby desirably allowing each of the electrical circuit boards to contain and/or include a relatively large amount of electrical components which efficiently and densely populate the respective boards.
Because many components densely populate these circuit boards, during use and/or operation of the circuit boards, substantial amounts of heat are produced and/or generated within relatively small areas of the circuit boards. This generated heat undesirably prevents the components from properly functioning and may even irrevocably damage or destroy these components. Therefore it is desirable to form, create and/or manufacture circuit boards that are adapted to disperse and/or dissipate heat away from such heat producing components.
Pipes, tunnels and/or caverns (e.g., heat pipes) may be used to disperse, dissipate and/or translate heat within these multi-layer circuit boards. Conventional heat pipes typically comprise an elongated material having an opening which extends through the length of the pipe. By way of example and without limitation, a conventional heat pipe is typically placed in electronics equipment with a first portion of the pipe being disposed near a warm or heat emitting portion of the equipment and a second portion of the pipe being disposed near a cool or heat absorbing portion of the equipment, thereby allowing the pipe to transfer heat away from the warm or heat emitting portion toward the cool or heat absorbing portion.
One drawback associated with these conventional heat pipes is that they are typically made and/or manufactured from additional materials that are not needed for the functioning of the electronics equipment within which the heat pipes reside. Employing heat pipes which use additional materials is especially undesirable in a multi-layer circuit board which is designed to support and/or contain several electrical components in a relatively small amount of space. For example and without limitation, such additional material would add both unwanted size and weight to multi-layer circuit boards. Additionally, the material within these types of heat pipes is typically stationary or motionless, which causes the transfer and/or dissipation of heat within these types of heat pipes to be relatively slow.
Consequently, there is a need for circuit boards created by a method which allows many small electrical components to densely populate respective layers within the circuit boards, while still allowing heat to be relatively quickly dissipated and/or dispersed away from components which emit substantial amounts of heat. Specifically, there is a need for a method of creating integrated acoustic cooling pipe arrays within multi-layer circuit boards wherein the pipe arrays are integrally formed within the circuit board such that no or very little excess material is needed to create the pipes, and which include fluid which is circulated within these pipes and which is effective to accelerate the dissipation of heat within these pipes.
It is a first object of the present invention to provide a method for forming heat pipes within multi-layer circuit boards which overcome the various previously delineated drawbacks of conventional heat pipes.
It is a second object of the present invention to provide a circuit board having heat pipes that are integrally and substantially formed within the circuit board, and which include a cooling material which is circulated through the heat pipes, thereby quickly and efficiently dissipating heat from the circuit board.
It is a third object of the present invention to provide a multi-layer circuit board including integrated acoustic cooling pipe arrays which allow heat energy to be efficiently and repeatedly transferred from warmer areas of the circuit board to cooler areas of the circuit board.
According to a first aspect of the present invention, a circuit board assembly is provided. The circuit board assembly includes a first circuit portion in which an amount of heat is generated; a heat pipe which is integrally formed within the first circuit portion; an amount of fluid which is disposed within the heat pipe; and a heat pump which is operatively disposed within first circuit portion and which communicates with he heat pipe and the amount of fluid, the heat pump being effective to produce pressure fluctuations within the amount of fluid, thereby causing the amount of fluid to circulate within the heat pipe and dissipate the amount of heat.
These and other objects, aspects, and advantages of the present invention will become apparent upon reading the following detailed description in combination with the accompanying drawings.